1. Field of the Invention
The present invention relates generally to the field of volleyball nets and other types of sports nets. More specifically, the present invention discloses a system for supporting and tensioning a volleyball net so that the top edge of the net is stretched by the same amount as the bottom edge of the net to maintain vertical alignment of the standards.
2. Statement of the Problem
In conventional volleyball nets, the upper edge of the net is subject to a much greater tensile force than the lower edge of the net. However, the predominant portion of this tensile force is carried by the net rope extending along the top edge of the net, rather than by the binding or the net itself. A problem tends to arise in those situations where the net is supported by means of two sleeves (e.g. made of vinyl) extending along the lateral edges of the net that slip over the upper portion of the standards. A lesser, although still substantial, tensile force must be carried by the binding (e.g., a vinyl tape) extending along lower edge of the net so that the volleyball rebounds from the net in the proper manner. In contrast to the upper tape, this tensile force is carried primarily by the lower vinyl tape which therefore tends to stretch more than the upper edge of the net. After this uneven stretching has progressed beyond a certain point, it becomes difficult to reassemble the net with proper tension on the bottom edge of the net unless the standards are tilted inward from vertical. Therefore, it is desirable to allow the upper tape to stretch to compensate for stretching of the lower tape, and thereby preserve the vertical orientation of the standards. In particular, the user should be able to adjust the vertical orientation of the standard and adjust the tensioning force on the top rope of the net independently of each other.
A number of devices have been invented in the past for supporting and tensioning volleyball nets, including the following:
______________________________________ Inventor Patent No. Issue Date ______________________________________ Stapleton 2,638,346 May 12, 1953 Mazzei, et al. 3,435,487 April 1, 1969 Barnes 3,940,139 Feb. 24, 1976 Burns 4,153,247 May 8, 1979 Chell British Patent March 5, 1980 Spec. 1562025 Pace 4,253,671 March 3, 1981 Stetter, et al. 4,720,112 Jan. 19, 1988 Wheeler 4,830,382 May 16, 1989 Pardi 4,844,477 July 4, 1989 Pohrer Des. 308,473 June 12, 1990 Stewart 4,968,042 Nov. 6, 1990 Stewart 4,973,059 Nov. 27, 1990 ______________________________________ "The KilKourt A Portable Outdoor Volleyball Court System" brochure by AA Sports, Inc., 3544 North Southport Avenue, Chicago, Illinois 60657 (1984)
Barnes and Stapleton disclose volleyball net assemblies using a winch to simultaneously tension both the upper and lower ropes of the net.
Mazzei, et al., disclose a stabilizer for releasable attachment to each end of a volleyball net. Each stabilizer includes a resilient connector for tensioning the net.
Burns discloses a ratchet mechanism for applying equal tension to the upper and lower ropes of a game net, as best shown in FIG. 4 of this patent.
Chell discloses a tennis net having a net rope 32 that is routed over a metal eyelet and held by a knot 35 at the base of the post. It appears that the net rope is not used for tensioning.
The Pace, Pohrer, and Pardi patents are examples of pulley and ratchet arrangements used to tension the net rope of a game net assembly.
Stetter, et al., disclose an adjustable height standard for net games. The standard is comprised of a pair of telescoping tubes. Each tube has a set of spaced holes formed in the tube wall. A hitch pin is inserted through various combinations of holes in the two tubes to select a desired height.
Wheeler discloses a portable volleyball net support system. One end of the upper net rope is directed downwardly along the standard through an eye bolt. The free end of the rope is secured by a oneway cleat attached to the standard.
The Stewart patents disclose a two volleyball net adjustment system in which winch and pulley arrangements simultaneously tension both the top and bottom net ropes.
The 1984 brochure by AA Sports, Inc., discloses a volleyball net tensioning system in which a compound pulley is used to adjust the tension placed on the upper rope of the net. A clam cleat positioned above the upper pulley is used to secure the upper net rope after appropriate tension has been applied. The lower rope of the net is separately tensioned by hand and then secured by means of a second cleat.
3. Solution to the Problem
None of the prior art references uncovered in the search show a support and tensioning system for volleyball nets having the structure of the present system. In particular, the present system allows the upper edge of the net to be stretched by the same amount as the lower edge of the net to preserve vertical alignment of the standards.